Quantitative analysis of citric acid/sodium hypophosphite modified cotton by HPLC and conductometric titration.
Quantitative analysis of citric acid/sodium hypophosphite modified cotton by HPLC and conductometric titration.
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DOI：
10.1016/j.carbpol.2014.12.028
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发表时间：
2015-05
影响因子：
11.2
通讯作者：
Tao Ye;Bijia Wang;Jian Liu;Jiangang Chen;Yiqi Yang
中科院分区：
文献类型：
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作者：
Tao Ye;Bijia Wang;Jian Liu;Jiangang Chen;Yiqi Yang
采用等度HPLC结合电导滴定法对柠檬酸（CA）/次磷酸钠（SHP）对棉纤维素的改性进行了定量研究。CA/SHP作为一种绿色交联剂被广泛应用于纤维素和其他碳水化合物聚合物的增韧改性，但其机理尚未得到深入的研究。目前的研究调查所有可识别的二级多元羧酸从CA分解CA/SHP-纤维素系统在各种固化条件下。结果表明，与理想的酯化反应相比，CA分解对温度更敏感。CA/SHP处理棉织物的抗皱性提高主要是由酯交联和SHP交联两种交联机理引起的。柠康酸（CCA）和/或衣康酸（IA）的低聚物被鉴定为织物泛黄的可能贡献者。最后，织物的抗皱性与多元醇添加CA/SHP交联体系中CA的保存密切相关。多元醇的剂量应保持在低于临界点，以保持对纤维素的不期望的竞争最小。高效液相色谱法与电导滴定法相结合可用于研究CA/SHP-纤维素交联体系。研究结果表明，更好地应用CA/SHP在多糖修饰一般。
Isocratic HPLC was used in conjunction with conductometric titration to quantitatively examine the modification of cotton cellulose by citric acid (CA)/sodium hypophosphite (SHP). CA/SHP had been extensively used as a green crosslinking agent for enhancement of cellulose and other carbohydrate polymers without in-depth understanding of the mechanisms. The current study investigated all identifiable secondary polycarboxylic acids from CA decomposition in the CA/SHP-cellulose system under various curing conditions. It was found that CA decomposition was more sensitive to temperature compared with the desirable esterification reaction. Two crosslinking mechanisms, namely ester crosslinking and SHP crosslinking were responsible for the observed improvement in crease resistance of CA/SHP treated cotton fabrics. An oligomer of citraconic acid (CCA) and/or itaconic acid (IA) was identified as a possible contributor to fabric yellowing. Finally, the crease resistance of fabrics correlated strongly with CA preservation in polyol-added CA/SHP crosslinking systems. The dosage of polyol should be held below an inflexion point to keep the undesirable competition against cellulose minimum. The combination of HPLC and conductometric titration was demonstrated to be useful in studying the CA/SHP-cellulose crosslinking system. The findings have implications for better application of CA/SHP in polysaccharide modifications in general.